I switched to trail shoes at about 25 pounds; now I rarely hike with more than 20 pound loads. I wouldn't switch back below 30.

I do like the GTX option - much of the time, it seems I'm on muddy trails, with perhaps one or two inch deep standing water. The GTX option keeps my feet drier, since I tend not to detour around such obstacles. It doesn't keep my feet appreciably drier in the rain, since water runs down into the shoes from my legs (no different than it did with ankle-high boots.)If I were sure I'd always be in drier areas, I'd forego GTX.

I've always been a Vasque partisan - Sundowners were my boot until I switched to the Breeze shoes; naturally, they no longer make the Breeze shoes. I tried on a couple of the models that allegedly replaced it in their line, but found the heel too loose. I just bought a pair of Patagonia drifters (GTX), which have felt fine on a couple of 3-mile dayhikes with a 5 pound load. Haven't worn them on an actual backpack trip yet, but they are comfortable.

However, don't be misled by what I like. The ONLY criteria for boots is how they feel on your feet. They must fit YOU, not me.